Technical Field
The instant disclosure relates to a refreshing method of background signal and a sensing device for applying the method, in particular, to a refreshing method of background signal for touch tracking and a sensing device for using the method.
Related Art
In the history of touch screen technology, the advancement from single point to multi-point touch sensing and touch tracking have always been the focuses of technological breakthroughs.
In recent periods, most of the touch screens for multi-point touch sensing and tracking of multiple touch points utilize the capacitive touch sensing system. This type of system relies on self-capacitance and/or mutual capacitance sensing methods to determine if the touch screen has being touched by the user. During the sensing period, when the controller of the sensing system has detected a change in capacitance for a particular location, the location is determined to have been touched by the user. Therefore, when the sensing system is in operation, each of the position coordinates is stored with its respective predetermined capacitance value (non-contact capacitance value). By this method, a comparison between the new capacitance value and the predetermined value can be done to determine if any position has been touched by the user.